Ultraviolet (UV) light has shorter wavelengths than visible light. Ultraviolet light is emitted by the sun. In particular, the sun emits ultraviolet A (“UVA”) radiation, ultraviolet B (“UVB”) radiation, and ultraviolet C (“UVC”) radiation. UVA radiation has longer wavelengths than UVB radiation or UVC radiation. UVA radiation, for instance, has wavelengths from 400 nm to 320 nm. UVB radiation, on the other hand, has wavelengths from 320 nm to 280 nm, while UVC radiation has wavelengths less than 280 nm.
Most of the ultraviolet radiation that passes through the Earth's atmosphere is UVA radiation. UVB radiation and UVC radiation, although smaller in presence, can be the most damaging to one's skin. For example, UVB radiation and UVC radiation have shorter wavelengths and therefore are the highest energy ultraviolet light. All forms of ultraviolet radiation, however, can be damaging to one's skin if left overexposed.
In the past, in order to protect oneself from the harmful effects of ultraviolet radiation, consumers have applied various sunscreens. Sunscreens, for instance, can be made with different Sun Protection Factor (SPF) values. The SPF values relate to the amount of protection that the sunscreen composition affords. SPF numbers, for instance, can range from as low as 2 to as high as 60. These numbers refer to the ability of the sunscreen product to screen or block out ultraviolet light, particularly UVA light. The SPF rating is calculated by comparing the amount of time needed to produce a sunburn on protected skin to the amount of time needed to cause a sunburn on unprotected skin. For example, ideally a person who applies sunscreen with an SPF value of 2 should be able to stay in the sun for twice as long without developing a sunburn. Similarly, if a person were to apply a sunscreen with an SPF value of 15, he/she should be able to remain exposed in the sun for 15 times longer before a sunburn develops.
Unfortunately, SPF values as applied to sunscreens are not always accurate. SPF values, for instance, do not always take into account the amount of B type or C type ultraviolet light present in the environment.
In view of the above, various manufacturers have recently developed ultraviolet sensors that are intended to help consumers monitor ultraviolet rays being admitted from the sun. Such UV sensors can, for instance, measure the amount of ultraviolet light present and provide a recommended exposure time based upon a person's skin type and/or the type of sunscreen that the person is using. For instance, the Chaney Instruments Company markets and sells a product called the UV Skin Care Sensor. The Vernier Software and Technology Company also markets and sells UVA sensors and UVB sensors.
The present disclosure is directed to further improvements in UV detection devices and is directed to further methods and products that are intended to assist consumers in preventing overexposure to UV radiation.